plasticity and functional recovery of the brain after trauma

Question 1

explain what brain plasticity is

Answer 1

• the brain’s tendency to change and adapt as a result of experience and new learning
• involves growth and new synaptic connections made. Peaking about 15,000 per neuron at 2-3 yrs old (Gopnik et al. 1999)
• as we age, rarely used connections are deleted and frequently used connections are strengthened known as synaptic pruning.

Question 2

who researched brain plasticity

Answer 2

Maguire et al. (2000)

Question 3

explain the research into brain plasticity

Answer 3

• Maguire studied the brains of London taxi drivers and found they had significantly more volume of grey matter in the posterior hippocampus than in a matched control group. This part of the brain is associated with the development of spatial and navigational skills.
• this makes sense considering that to become a taxi driver you have to take a knowledge test which assesses their recall of the city streets and possible routes
• also found that the longer they had been taxi drivers the more pronounced was the structural difference (positive correlation)

Question 4

who else conducted research into brain plasticity?

what did they find?

Answer 4

• Graganski et al (2006)
• studied brains of medical students three months before and after taking their final exams.
• learning induced changes were seen to have occurred in the posterior hippocampus in the parietal cortex presumably as a result of learning.

Question 5

explain functional recovery after brain trauma

Answer 5

• unaffected areas of the brain are often able to adapt and compensate for those areas that are damaged.
• the functional recovery that may occur is an example of brain plasticity.
• scientists suggest that this may occur very quickly after trauma and then slow down after several weeks or months

Question 6

what happens in the brain during recovery

Answer 6

• brain is able to re-wire and reorganise itself by forming new synaptic connections close to the area damaged
• secondary neural pathways that would not be typically used to carry out certain functions are activated to enable functioning to continue (Doidge 2007)

Question 7

what structural changes happen in the brain during recovery? (3)

Answer 7

• Axonal sprouting= growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
• denervation super sensitivity= axons that do a similar job become aroused to a higher level to compensate for the ones lost. However it can have negative consequences of oversensitivity to messages such as pain.
• recruitment of homologous areas on opposite sides of the brain = means that specific tasks can still be performed. E.G. if Broca’s area on the right was damaged, the left side would be able to take over.